Automatic timer



y 1949' H. L. ABRAHAMSE ET AL 2,468,855

AUTOMAT IC TIMER 3 She'ets-Sheet 2 Filed Sept. 8, 1945 IN VEN TOR. Aft/V6) 4, AJWAMJE BY JOHN E. HEW/7'7 W/dzzw y 1949. H. L. ABRAHAMSE ET AL 2,468,855

AUTOMATIC TIMER 3 Shets-Sheet 3 Filed Sept. 8, 1945 5 m i 4 a INVENTOR. HEN?! 4, 4124mm: BY JOHN. E. Hit W77 Patented May 3, 1949 r AUTOMATIC TIMER Henry L. Abrahamse and John E. Hewitt, Lansing,

Mich., assignors to Abrams Instrument Corporation, Michigan Lansing, Mich, a corporation of Application September 8, 1945, Serial No. 615,200

2 Claims. 1

This invention relates to automatic timing devices, particularly those of the electrically operated class.

The principal object of the invention is to provide an extremely accurate regulatable timer capable of controlling the period of closure of a timed electrical circuit, or for opening a normally closed circuit for a predetermined time.

Another object is to provide a timer of this character of particularly simple and compact construction.

Another object of the invention is to provide a timer which can be selectively operated by means of a switch on the timer case or by aremote control switch such as the platen switch of an electric photographic printer.

Another object of the invention is to provide a timer, the timed operation of which can be controlled either through a switch on the timer case or by a remote control switch such as the aforementioned platen switch.

A still further object is to provide a novel form of electrically operated clutch,

These objects will more fully appear in the following specification when read in connection with the accompanying drawings, wherein:

Figure 1 is a front elevational view of a timer embodying the invention, portions being broken away to disclose the construction thereof;

Figure 2 is a cross-sectional view taken on substantially the line 22 of Figure 1;

Figure 3 is a cross-sectional view of the timer on substantially the line 3-3 of Figure 2, with the timer case removed;

Figure 4 is a front elevational view of a clutch mechanism, a portion of the clutch housing being removed to more clearly disclose the construction thereof;

Figure 5 is a cross-sectional view taken on substantially the line 5--5 of Figure 4;

Figure 6 is a wiring diagram of the timer shown in conjunction with an electric photographic printer;

Figure 7 is a bottom view of the flying arm switch assembly;

Figure 8 is a front elevational view of the same; and

Figure 9 is an end elevational view thereof.

In general the timer is designed to send out a continuous electrical impulse, when power is applied, for a predetermined length of time. The end of the timed interval is determined by a switch contact adapted to be opened by an oscillatory flying arm. The arm is driven in one direction at constant speed by an electric motor through an electrically controlled switch. The duration of the time interval is controlled by varying the distance the flying arm must move before opening the switch contact.

The timer comprises a governor controlled constant speed motor I I) mounted on a frame 9. The motor l0 drives a flying arm ll through a reduction gear train l2 and electro-magnetically actuated clutch l3. The flying arm is adapted to open one or both of a pair of contacts 60 and GI, as will more clearly appear presently, of which contact 60 controls the timed circuit. The timed interval is regulated by means of a knob l4 and dial 23.

The case I5 is a generally rectangular box formed in two parts joined together along the line IS. The front of the case forms a panel for supporting a start switch ll, an enlarger printer switch IS, a timer switch l9, and a light switch 20. The start switch H is a spring returned Push button switch, while switches I 8, l9 and are conventional small toggle switches. In addition, a signal light 2|, preferably is mounted on the panel. I

The panel is provided with a window opening 22 therethrough through which a circular dial 23 may be viewed. The dial 23 is secured by screws 24 to the hub of a dial gear 25. The dial gear hub is rotatable in a bearing 26 mounted in a central opening in a plate 2'! which is secured to the inner face of the panel of he case IS in spaced relation thereto. The dial gear has a flying arm stop 34 of circular cross-section attached to its rear surface adjacent the periphery of the gear.

The knob M is aifixed to a shaft 28 which extends through the panel of the timer case and carries a driving pinion 29 thereon which meshes with the teeth of the dial gear 25. Also rigidly attached to the shaft 28 is a toothed detent gear 30, the teeth of which are engaged by a spring pressed detent 3| attached to the plate 2'l. The detent gear 36 and detent 3! hold the shaft in any set position, and as the dial gear and dial 23 are rotated by the pinion 29, they are also held in adjusted position.

A shaft 32 is mounted at its front end in a bearing in the dial gear and its rear end is located in the clutch I3 as will be more fully described later. The fiying arm I I is keyed or otherwise affixed to the shaft 32 so asto rotate therewith in a clockwise direction when viewed from the front of the panel. One end of a long coiled spring 35 is attached to the flying arm stop 34. The spring is wrapped several times around the shaft 32 and is attached to the flying arm H. A flying arm spring retainer 35 between the spring 35 and dial gear 25 assists in holding the spring in position.

The clutch 13 comprises a housing 31 which is rigidly attached'by suitable supporting posts 55 to the frame 9 mounted within the timer case. The clutch housing is composed of two halves 45 secured together by screws. The shalt 32 mentioned above extends through the front of the clutch housing and has formed on its inner end a radial disk H. The disk 4| carries three planetary gear pinion; spaced from each other and revolubly mounted on shafts 45. Surrounding the planetary gear pinions 42 and rotatably mounted thereon is a ring gear 44, the radially outer surface of which is cylindrical. -A sun gear 45 is carried by a shaft 46 which is mounted in a bearing in the back part of the clutch housing and meshes with the three planetary gears 42.

A pair of clutch members 41 of generally semicircular shape surround the outer surface of the ring gear 44. The two lower ends oi'the clutch members 41 are pivotally connected by a pin 45 to the gear housing. The other ends of the clutch members 41 extend past each other in overlappingrelationship and then extend parallel for a short distance as at 49 and 50. The two ends 49 and 50 are connected together by a coiled tension spring which normally separates the clutch members and completely disengages them from the outer surface of the ring gear 44. A cam 52, rotatable in bearings in the clutch housing, is located between the ends 49 and 50 so that when rotated in one direction it overcomes the tension of spring 5| and causes the clutch members to engage the ring gear to prevent it from rotating. When rotated in the opposite direction the cam 52 releases the ends 49 and 55 and permits the spring 5i to disengage the clutch members from the ring gear so that it can rotate as a unit about the pinions 42.

The axially rear end of shaft 45 carries a gear 53 which is the final gear of the gear train I2 mentioned above. This gear train 12 is connected to the shaft of the motor in any suitable manner so as to drive the sun ear 45 of the planetary clutch.

A solenoid 54 is mounted on the frame 9 and reciprocates up and down, as viewed in Figure 3, when the solenoid is energized anddeenergized. The armature 55 of the solenoid is connected by a pin and slot connection 55 to an arm 51 attached to the shaft of the cam 52 So that as the armature 55 reciprocates vertically the cam is rotated in the manner mentioned above.

In addition to the elements mentioned above, a load relay 58 is mounted in any suitable position within the timer case. This load relay is a solenoid relay operating a single pole, double contact switch.

The flying arm switch contact 50 and motor switch contact 5| are mounted on a bracket 21a of angular cross-section fixed to the back of plate 21. The two contacts are located adjacent each other. Contact 65 is rigidly connected to the plate 21, while contact 5| is mounted on one end of a. leaf spring 58 having its other end fixedly attached to the plate 21. A contact-arm 51 is pivotally connected by pivot 80 to the bracket 21a. The contact arm 51 is provided with an extension 61a having depending therefrom a lug 51b which is located in the path of the flying arm H. The contact arm is biased toward the contacts 50 and BI by a suitable spring iii, and normally touches both contacts. The contact arm 51 is located relative to the contacts 55 and 5| so that as the contact arm is moved in a direction away from the contacts it immediately breaks away from the flying arm contact 55, while the spring 55 carrying contact 5| causes the latter to follow the contact arm for a short distance before breaking contact between them.

When the flying arm ll nears the end oi its oscillatory movement at the end of the timed period, it strikes contact arm 51 and moves it away from contact 55. A slight further movement of flying arm I l causes it to move the contact arm 51 still further and break its connection with contact 5|.

The timer is connected, as indicated in the wiring diagram in Figure 6, to a conventional photographic printer by means of a four prong plug. The prongs are indicated by numerals 52, 53, 54 and 55. In the circuit of the printer is a platen switch 55 which is closed when the platen of the printer is lowered to closed position. The printer contains a plurality oi printing lights 1| connected in parallel as indicated in Figure 6. The printer also contains a pair 0! viewing lights 12 which may be turned on by switch 14 when arranging the negative in position. A pair of colored safe lights 13 are also provided. They may be turned on by means of a switch 15.

Normally when the timer is connected as shown and intended to automatically operate a printer, the knob I4 is rotated to adjust the dial 23 to the required period of closure 01' the timed printer circuit. This operation of the dial rotates the dial gear 25 and flying arm stop 34 toward or away from the contact arm 51. When the flying arm stop moves, the flying arm II is moved with it so as to vary the distance, and consequently the time for the flying arm to contact the arm 61 and cause it to open contact 55 after the timer is started. Also the enlarger-printer switch is thrown to enlarger position, or that position marked E in Figure 6, and timer switch I! is closed to start the motor. After the time interval is adjusted, the timer circuit is closed, either by pushing the start switch l1 or closing the platen switch 55. Closing either of these switches energizes the clutch solenoid 54, as well as the relay coil 55. The energization of the clutch coil 54 operates the cam 52 so that the clutch arms 41 engage the ring gear 44, stopping it from rotating. The rotation of shaft 45 is transmitted through the planetary gears 42 and sun gear 45 to the flying arm and the flying arm begins to rotate. At the same time the relay coil 55 closes switch 59 and turns on the lights 1| in the printer. It also closes a holding circuit for clutch solenoid 54 through the enlarger-printer switch I5. Then even it the start switch is released, the timer continues to operate until the indicated time has elapsed. The flying arm continues to rotate for the required number of seconds, which it takes to reach contact arm 51 and cause it to open contact 55. As soon as contact 55 opens, the relay coil 55 is deenergized, switch 59 opens, turning oi! the printer lights. It also deenergizes the clutch coil 54 which releases the clutch, and spring 55 returns the flying arm to the stop 34. The instrument will not recycle until either platen switch 55 or start switch 11 is again closed. To start another cycle it will only be necessary to push switch l1 or close the platen on the printer.

11 after start switch l1 or platen switch 55 is closed, it is held closed until the flying arm opens contact 55, the relay coil 55 will be deenergized and the printer lights 1| turned on, but the motor will continue to run and the flying arm and contact arm ll continue to move until the latter moves away from contact I and breaks the motor circuit. The motor will then stop and will not again start, nor will the flying arm return to 1 the dial has been adjusted to any predetermined time and the timer set in motion, the operator has no control over the duration of closure of the timed circuit other than by means or the timer switch it. Opening this switch cuts oil! the power power and stops the entire timer including the motor. To obviate this, and give the operator some control over the timer, if desired, as a safety feature, or for any other reason, the enlarger-printer switch can be set to the printer position indicated by the letter P in Figure 6. Then when either the start switch II or platen switch 80 is closed, the relay coil 50 and clutch solenoid 54 will be energized, the lights in the printer turned on, and the timer will start its timed cycle. If either switch I! or it is held in closed position for the duration or the timed cycle the timer will operate as before, the flying arm first opening the contact 60 and then contact ii to stop the motor. However, the timer may be stopped at any time, and the lights in the printer immediately turned 01!. even before the end of the timed cycle, by releasing start switch I! or opening platen switch ll, whichever happens to be closed. As soon as the switch I or I1 is opened, the clutch coil circuit will be broken and the flying arm will be returned to its start position.

If it is desired to adjust a negative or estimate its transparency, the light switch 20 can be closed. This turns on the lights in the printer which will remain on until the switch 2. is opened.

From the foregoing it will be seen that the present invention provides a simple, economical timer of very accurate operation. It is easily adjusted to any number oi seconds and it is'positive in operation Also, it can be set to operate either automatically or manually by a switch directly on the printer or by a switch on the timer.

The scope or the invention is indicated in the 990N181 claims.

We claim:

1. An automatic timer comprising a support, a unidirectional electric motor mounted on said support, oscillatory switch operating means mounted on said support, means including a clutch adapted to connect said motor to said switch operating means, electro-magnetic means mounted on said support and associated with said clutch fo engaging and disengaging the latter, a circuit for said electro-magnetic means including a relay switch, a relay coil associated with said relay switch for closing the latter when said relay coil is energized, and a circuit for said relay coil including a switch mounted on said support and associated with said oscillatory switch operating means, said last named switch being adapted to be opened by said oscillatory switch operating means in one position of oscillation thereof.

2. An automatic timer comprising a support, a unidirectional motor mounted on said support, oscillatory switch operating means mounted on said support, an electrically energized clutch associated with said motor and said oscillatory switch operating means for selectively connecting said motor and switch operating means together, an electric circuit for said clutch including a starting switch, a, relay switch in parallel with said starting switch, a holding relay in series with said relay switch and said startin switch, and a third switch in series with said relay, said third switch being mounted on said support in the path of said oscillatory switch .operating means and adapted to be opened by the latter upon the predetermined movement thereoi in one direction.

HENRY L. ABRAHAMSE. JOHN E. HEWI'I'I.

REFERENCES CITED The following references are of record in the me of this patent: 

